Thanks for getting back with me so quickly!!! That's what I had initially thought Mustang5L5. After going through several decoding sites and even reading that Ford didn't cast any newer blocks until the 94- 95 model years?, that the numbers on my block actually was used for 91-93. Was even reading that ALL XXX blocks were either production and/or replacement engines. I wish someone could point me the right direction on literature,or just know what is or isn't right.
Thanks again
Charlie
The F1SE block is very common. It was originally engineered for a 1991 Thunderbird (F1S = 1991 Thunderbird) but it was used in other models. The '91+ Mustang also used that block. It's a roller block.
If you want to know exactly what vehicle the engine came from, you need to locate the partial VIN that is stamped on the flat area on the top rear, right behind where the lower intake manifold would sit. If it's original, it will match your cars VIN
That's the problem...there aren't any stampings in/or around that location. Only codes on the block are what I posted and the XXX inside the lifter valley,and it is a roller block. I was under the impression that it was a replacement engine. Maybe warranty issue,not sure...
My interest is knowledge...plain and simple. Wasn't implying that XXX was a replacement. If it's a possible original then why NO partial VIN code @ the rear of the block? There are no grind marks and I've switched it over to carb. I looked it all over before taking to the machine shop and haven't missed any markings.
If no VIN, then it's possible the engine was replaced. If done so by Ford, it would be a rebuilt long block. If you call a local dealer with the VIN they might be able to tell you the service history
Were there any numbers cast on the flat pad above the starter, behind the engine mount?
As for possible original parts, including block, in a 1991 car, parts can be dated before the year model of the car, but not later than.
You could hunt down the casting date on the block, and compare it to the build date of your car.
So long as the casting date of the block is before the build date by at least a couple weeks, you can narrow down if the block is wrong. You can never tell it is 'right' though, without the VIN. You can just narrow it down to likely, but not positive.
Another problem.....The 91 GT that the engine come out of was totaled 5 years ago. I bought the engine,being that it was the only thing unharmed from a rollover crash and fire. I've got an 87 5.0 liter GT 5 speed that I use for 1/8th mile duty,that's where the engine now resides.
No numbers behind the engine mount either. This is why I'm completely in the dark on it. I've got so many different year parts in the engine while rebuilding it,I guess it really doesn't matter. Was just looking for clarification,had never seen a "not so defining" block from Ford before. Ran into this problem on a 5.7 liter project a few years back. A buddy built a 95 V8 S10 the block(factory roller) had the same issues(No defining #'s), upon further research it was determined that it was a Canadian replacement long block,and that's what you got. And I know my engine IS NOT Canadian!!!
Maybe i'm confused since I wouldnt expect there to be more marks on the block. The only marks I know of are the casting numbers which you have pics of, and a partial VIN. That's really it. There might be XXX or YYY in the valley, but the meanings of these are unknown as well.
Even the T-5 transmission has a partial VIN on it if it's a factory trans.
But lots of times these numbers rust over and obscure and nobody sees them. But for the most parts, there's not a whole lot you can do to identify an engine, especially one 20+ years old where who knows what has been replaced. Engineering part numbers can be confusing too because the digit doesn't always signify the year of production. As we all know, E7 years could come brand new on a 1993 Mustang, so they certainly aren't 1987 heads.